1. Technical Field
The present invention relates to a mask holding structure, a film forming method, an electro-optic device manufacturing method, and an electronic apparatus.
2. Related Art
An organic electroluminescence (EL) panel, which is a type of electro-optic device, has a self luminous display device having a laminated structure of thin films. A manufacturing process of an organic EL panel includes a film forming step in which a thin film pattern that constitutes construction layer of the display device is formed on a substrate.
As a method of forming a thin film pattern, an evaporation method that uses a metal mask (for example, see Japanese Unexamined Patent Application, First Publication No. 2001-237073) is known. In the evaporation method that uses a metal mask, it is difficult to manufacture a highly precise metal mask that corresponds to a large size substrate on which the film is to be formed. Moreover, since the thermal expansion coefficient of the metal mask is far greater than that of a glass substrate for an organic EL panel, pattern displacement occurs easily.
A method for manufacturing a mask using a silicon substrate which has a thermal expansion coefficient proximate to that of glass, has been proposed. In this method, an aperture pattern that corresponds to the film forming pattern is formed on a silicon substrate using semiconductor manufacturing techniques such as photolithography and dry etching.
In the mask manufacturing technique that uses the silicon substrate, the silicon substrate (silicon chip) on which the aperture pattern is formed, is attached to a supporting frame of the mask. However, in the case of corresponding to a large sized substrate on which a film is to be formed, distortion or deflection of a large sized supporting frame may cause a decrease in pattern precision.